Former U.S. Secretary of State Hillary Rodham Clinton speaks to members of the Institute of Scrap Recycling Industries during their annual convention in Las Vegas, Nevada.Reuters

Former US Secretary of State Hillary Clinton was in favour of arming Syria's rebels to turn the balance of power against Syrian President Bashar al-Assad in the country's protracted civil war before being overruled by President Barack Obama.

A copy of Clinton's soon-to-be-released book was obtained by CBS News and she speaks candidly about her views on the Syrian civil war and her relationship with Obama.

"Wicked problems rarely have a right answer; in fact, part of what makes them wicked is that every option appears worse than the next. Increasingly that's how Syria appeared," Clinton wrote, according to CBS News.

Clinton said that she was convinced that if the US was to send arms to moderate rebels and equip them with the right training, the tide of the civil war could be turned against Assad.

"The risks of both action and inaction were high, [but] the president's [Obama's] inclination was to stay the present course and not take the significant further step of arming rebels," she added.

"No one likes to lose a debate, including me. But this was the president's call and I respected his deliberations and decision."

Clinton, who lost out on the 2008 Democratic nomination to Obama, moves on to talk about her relationship with the Chief of Staff behind closed doors.

"From the beginning of our partnership, he had promised me that I would always get a fair hearing. And I always did. In this case, my position didn't prevail," she wrote.

She talks of her first meeting with Obama after he was nominated to run in the 2008 presidential race at which the pair "stared at each other like two teenagers on an awkward first date."

"Both Barack and I and our staffs had long lists of grievances. It was time to clear the air," she wrote.

Her memoirs are released on 10 June and are set to reveal all about her time as US Secretary of State. It is being viewed as the beginning of her campaign to run for presidency in 2016.